The present invention relates generally to communication devices, and is specifically concerned with communication between persons wearing full face masks.
Typically, persons working in a hostile environment are required to wear full face masks in order to protect themselves against the hazards of the environment. These masks include full face mask respirators, self-contained breathing apparatus, and air supplied masks.
The object is to prevent the wearer of the mask from breathing in any harmful fumes from the environment. To this end, the face mask normally must be adequately sealed to prevent entrance of the harmful fumes into the mask. In addition, a positive pressure must be maintained at all times within the mask. In this way, if the mask is somehow punctured, the positive pressure within will force the air being supplied to the face mask to exit the mask through the puncture and, thereby, prevent the passage of harmful environmental air back through the puncture and into the mask.
Usually full face masks intended for use in hostile environments must be approved or certified by a government or other certifying body. For this approval to be granted, the face masks must comply with certain strict regulations that require that the masks undergo a series of tests to ensure the protection of the user. One such test verifies the sealing integrity of the mask. Once a mask has been approved, any changes made to the mask which effect the seal may require additional approval by the regulating body.
The mask when located over the face and mouth, however, typically causes diminished or disturbed communication between individual wearers of such masks often to the point where communication between the users is not possible. The mask seal while acting to block out the infiltrating harmful gas also invariably suppresses voice communication. Thus, an individual speaking while wearing a full face mask can not ordinarily be heard clearly by someone else.
Voice communication in such hostile environments is highly desirable and frequently necessary. It is known to provide the user with a microphone within the mask that is coupled to a speaker outside the mask. However, in order to connect the microphone to the speaker, the seal of the mask may be compromised. The fitting of pre-approved face masks with such a communication system would normally require new approval of the face mask. Considerable expense, however, can be involved in both the equipping of the existing pre-approved face masks with these prior art communication systems, and in obtaining new approvals for the masks. This expense has led to a work place setting where the use of noncommunication face masks is the standard. Workers typically rely on outdated visual signals which may be ineffective in environments where visibility is low.